Lithium-iron disulfide primary battery

Abstract

There is provided a lithium-iron disulfide primary battery capable of suppressing the elevation of the open circuit voltage during the storage of battery. The lithium-iron disulfide primary battery has a positive electrode, which has iron disulfide as a cathode active material, including a cathode composition layer formed on a cathode current collector, a negative electrode including lithium as an anode active material, and an electrolytic solution including an electrolyte dissolved in an organic solvent. The organic solvent includes at least an alkylamide solvent. By this construction of the battery, the elevation of the open circuit voltage of the lithium-iron disulfide primary battery during the storage may be suppressed. Therefore, even after being stored for a long term, the lithium-iron disulfide primary battery can maintain compatibility with 1.5-V class primary batteries and the like.

1 . A lithium-iron disulfide primary battery comprising: 
 a positive electrode including iron disulfide as a cathode active material;    a negative electrode including lithium as an anode active material; and    an electrolytic solution including an electrolytic solution dissolved in an organic solvent,    wherein the organic solvent includes an alkylamide solvent represented by the following formula (1):                          wherein each of R 1  to R 3  represents a hydrogen group or a linear alkyl group.    
     
     
         2 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the alkylamide solvent includes at least one solvent selected from a group consisting of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and N,N-diethylformamide (DEF).  
     
     
         3 . The lithium-iron disulfide primary battery according to  claim 1 , wherein a content of the alkylamide solvent in the organic solvent is 5 to 100% by volume.  
     
     
         4 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the organic solvent includes the alkylamide solvent and a chain ether solvent.  
     
     
         5 . The lithium-iron disulfide primary battery according to  claim 4 , wherein the chain ether solvent is 1,2-dimethoxyethane (DME).  
     
     
         6 . The lithium-iron disulfide primary battery according to  claim 4 , wherein a content of the chain ether solvent in the organic solvent is 95% by volume or less.  
     
     
         7 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the organic solvent includes the alkylamide solvent and a cyclic ether solvent.  
     
     
         8 . The lithium-iron disulfide primary battery according to  claim 7 , wherein the cyclic ether solvent includes at least one solvent selected from a group consisting of 1,3-dioxolane (DOL), 4-methyl-1,3-dioxolane (4MeDOL), tetrahydrofuran (THF), and 2-methyltetrahydrofuran (2MeTHF).  
     
     
         9 . The lithium-iron disulfide primary battery according to  claim 7 , wherein a content of the cyclic ether solvent in the organic solvent is 95% by volume or less.  
     
     
         10 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the organic solvent includes the alkylamide solvent and a chain carboxylic acid ester solvent.  
     
     
         11 . The lithium-iron disulfide primary battery according to  claim 10 , wherein the chain carboxylic acid ester solvent is methyl propionate (MP).  
     
     
         12 . The lithium-iron disulfide primary battery according to  claim 10 , wherein a content of the chain carboxylic acid ester solvent in the organic solvent is 95% by volume or less.  
     
     
         13 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the organic solvent includes the alkylamide solvent and a chain carbonic acid ester solvent.  
     
     
         14 . The lithium-iron disulfide primary battery according to  claim 13 , wherein the chain carbonic acid ester solvent includes at least one solvent selected from a group consisting of ethyl methyl carbonate (EMC) and diethyl carbonate (DEC).  
     
     
         15 . The lithium-iron disulfide primary battery according to  claim 13 , wherein a content of the chain carbonic acid ester solvent in the organic solvent is 95% by volume or less.  
     
     
         16 . The lithium-iron disulfide primary battery according to  claim 1 , wherein the organic solvent includes the alkylamide solvent and a mixed solvent of at least two solvents selected from a group consisting of a chain ether solvent, a cyclic ether solvent, a chain carboxylic acid ester solvent, and a chain carbonic acid ester solvent.  
     
     
         17 . The lithium-iron disulfide primary battery according to  claim 16 , wherein a content of the mixed solvent in the organic solvent is 95% by volume or less.  
     
     
         18 . The lithium-iron disulfide primary battery according to  claim 1 , wherein a potassium salt is added to the electrolytic solution.  
     
     
         19 . The lithium-iron disulfide primary battery according to  claim 18 , wherein the potassium salt includes at least one member selected from a group consisting of potassium fluoride (KF), potassium chloride (KCl), potassium bromide (KBr), potassium iodide (KI), and potassium trifluoromethanesulfonate (KCF 3 SO 3 ).  
     
     
         20 . The lithium-iron disulfide primary battery according to  claim 18 , wherein the potassium salt concentration relative to the organic solvent is 0.05 to 0.5 mol/l.  
     
     
         21 . The lithium-iron disulfide primary battery according to  claim 18 , wherein the potassium salt concentration relative to the alkylamide solvent is 1.0 mol/l or less.